Altered somatosensory evoked potentials associated with improved reaction time in a simple sensorimotor response task following repetitive practice.

Introduction Repetitive practice of sensorimotor tasks is widely used for neurorehabilitation; however, it is unknown how practice alters sensory processing (e.g., recognition, discrimination, and attentional allocation) and associated cognitive processing, such as decision-making. The purpose of this study was to investigate whether long-latency somatosensory evoked potentials (SEPs) reflecting sensory processing, attention, and decision-making are altered by sensorimotor learning. Methods Fifteen participants performed a simple sensorimotor response task (thumb opposition in response to surface electrical stimulation), with experimental recording sessions before and after three days of practice. We then compared multiple SEP waveforms and reaction times (RTs) between pre- and postpractice trials. Results The RT was reduced after practice of three days, and we found a significant positive correlation between Delta RT and Delta N140(lat)at F3, Cz, and C3 ', Delta RT and Delta N250(lat)at F3, and there was a significant negative correlation between Delta RT and Delta P300(amp)at C3 '. Conclusion The present study suggests that motor learning improves somatosensory processing and attentional allocation via neuroplasticity and that these alterations are reflected by specific SEP changes.